<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<script src="../js/vue.js"></script>
<div id="app">
  {{message}}
  <h2 v-if="score>=90">优秀</h2>
  <h2 v-else-if="score>=80">良好</h2>
  <h2 v-else-if="score>=60">合格</h2>
  <h2 v-else>不合格</h2>

  <h2>{{result}}</h2>
</div>

<script>
  const app = new Vue({
    el: '#app',
    data: {
      message: "第一次，系统的学VUE",
      score:98
    },
    computed:{
      result(){
        let grade='';
        if(this.score>=90){
          grade="优秀";
        }else if(this.score>=80){
          grade="良好";
        }else if(this.score>=60){
          grade = "合格";
        }else{
          grade="不合格";
        }
        return grade;
      }
    }
  })
</script>

</body>
</html>